Get rid of complex ping-pong mechanism and replace it with simpler
single buffer flipping code.

The LCDC HW appears to be designed mainly static framebuffers in
mind. There are two modes of operation, either static single buffer,
or ping pong double buffering with two static buffers switching back
and forth. Luckily the framebuffer start address is fetched only in
the beginning of the frame and changing the address after that only
takes effect after the next vertical blank. The page flipping code can
simply write the address of the new framebuffer and the page is
flipped automatically after the next vertical blank. Using the ping
pong double buffering makes the flipping code way more complex and it
does not provide any benefit, so it is better to switch to single
buffer operation.

There is still one problem in updating the framebuffer dma address on
the fly. There are two registers defining the framebuffer dma area and
things may break if the dma address is fetched in while the registers
are are being updated.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
[Added description to the patch]
Signed-off-by: Jyri Sarha <jsarha@ti.com>

Cleanup irq handling. Clear the irq status unconditionally and
restructure the status bit conditions.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
[Added description to the patch]
Signed-off-by: Jyri Sarha <jsarha@ti.com>

Remove broken error handling. The condition for handling the
LCDC_SYNC_LOST and LCDC_FIFO_UNDERFLOW could never be satisfied as the
LCDC_SYNC_LOST interrupt is not enabled. Also the requirement to have
both LCDC_SYNC_LOST and LCDC_FIFO_UNDERFLOW fired at once before
handling the error looks weird.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
[Added description to the patch]
Signed-off-by: Jyri Sarha <jsarha@ti.com>

Split reset to a separate function and use usleep_range(250, 1000)
instead of msleep(1) to to keep the reset bit on long enough.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
[Added description to the patch, changed mdelay(500) to usleep_range(250, 1000)]
Signed-off-by: Jyri Sarha <jsarha@ti.com>

Disable crtc on unload. Call tilcdc_crtc_dpms() with DRM_MODE_DPMS_OFF
in the beginning of unload function.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
[Added description to the patch]
Signed-off-by: Jyri Sarha <jsarha@ti.com>

Cleanup runtime PM handling. Before the patch the usage of pm_runtime
calls was inconsistent and hard to follow. After the update the
pm_runtime calls are removed from set_scanout() and called around
major operations that access the HW. After the patch the DPMS code does
not have pm_runtime_forbid/allow calls any more and
pm_runtime_irq_safe() is not set anymore.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
[Added description to the patch]
Signed-off-by: Jyri Sarha <jsarha@ti.com>

Allocate suspend/resume register storage based on the actual number
registers the driver is aware of. The static allocation for register
storage had fallen behind badly.
Reported-by: Michael Bode <michael@bumbleB.de>
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

Fix build error when !CONFIG_CPU_FREQ
drivers/gpu/drm/tilcdc/tilcdc_drv.c: In function 'tilcdc_load':
drivers/gpu/drm/tilcdc/tilcdc_drv.c:327:1: error: label 'fail_put_clk' defined but not used [-Werror=unused-label]
 fail_put_clk:
 ^
Signed-off-by: Grygorii Strashko <Grygorii.Strashko@linaro.org>
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

There is nothing special about tilcdc HW when the video memory is
concerned. Just using the standard drm helpers for implementation is
enough.
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

The LCD controller must be deactivated and all DMA transactions stopped
when the suspend power state is entered otherwise the PRCM causes the L3
bus to get stuck in transition state.

This commit forces the lcdc to be shut down and waits for all pending DMA
transactions to complete as part of the suspend handler for this driver.
Signed-off-by: Darren Etheridge <detheridge@ti.com>
Tested-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

The frame_done interrupt was only being enabled when the vsync
interrupts were being enabled by DRM.  However the frame_done is
used to determine if the LCD controller has successfully completed
the raster_enable, raster_disable commands and the vsync interrupts
are not always enabled during these operations.
Signed-off-by: Darren Etheridge <detheridge@ti.com>
Tested-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

On BeagleBone Black if no HDMI monitor is connected and suspend
is requested a kernel panic will result:

root@am335x-evm:~# echo mem > /sys/power/state
[ 65.548710] PM: Syncing filesystems ... done.
[ 65.631311] Freezing user space processes ... (elapsed 0.006 seconds) done.
[ 65.648619] Freezing remaining freezable tasks ... (elapsed 0.005 seconds) done.
[ 65.833500] Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa30e004
[ 65.841692] Internal error: : 1028 [#1] SMP ARM
  <snip>
[ 66.105287] [<c03765f0>] (platform_pm_suspend) from [<c037b6d4>] (dpm_run_callback+0x34/0x70)
[ 66.114370] [<c037b6d4>] (dpm_run_callback) from [<c037ba84>] (__device_suspend+0x10c/0x2f4)
[ 66.123357] [<c037ba84>] (__device_suspend) from [<c037d004>] (dpm_suspend+0x58/0x218)
[ 66.131796] [<c037d004>] (dpm_suspend) from [<c008d948>] (suspend_devices_and_enter+0x9c/0x3c0)
[ 66.141055] [<c008d948>] (suspend_devices_and_enter) from [<c008de7c>] (pm_suspend+0x210/0x24c)
[ 66.150312] [<c008de7c>] (pm_suspend) from [<c008cabc>] (state_store+0x68/0xb8)
[ 66.158103] [<c008cabc>] (state_store) from [<c02e9654>] (kobj_attr_store+0x14/0x20)
[ 66.166355] [<c02e9654>] (kobj_attr_store) from [<c0185c70>] (sysfs_kf_write+0x4c/0x50)
[ 66.174883] [<c0185c70>] (sysfs_kf_write) from [<c018926c>] (kernfs_fop_write+0xb4/0x150)
[ 66.183598] [<c018926c>] (kernfs_fop_write) from [<c0122638>] (vfs_write+0xa8/0x180)
[ 66.191846] [<c0122638>] (vfs_write) from [<c01229f8>] (SyS_write+0x40/0x8c)
[ 66.199365] [<c01229f8>] (SyS_write) from [<c000e580>] (ret_fast_syscall+0x0/0x48)
[ 66.207426] Code: e595c210 e5932000 e59cc000 e08c2002 (e592c000)

This is because the lcdc module is not enabled when no monitor is detected
to save power.  However the suspend handler just blindly tries to save the
lcdc state by copying out the pertinent registers. However module is off
so no good things happen when you try and access it.

This patch only saves off the registers if the module is enabled, and
then only restores the registers on resume if they were saved off during
suspend.
Signed-off-by: Darren Etheridge <detheridge@ti.com>
Tested-by: Dave Gerlach <d-gerlach@ti.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

Update tilcdc driver to set the state of the pins to:
- "default on resume
- "sleep" on suspend

By optionally putting the pins into sleep state in the suspend callback
we can accomplish two things.
- minimize current leakage from pins and thus save power,
- prevent the IP from driving pins output in an uncontrolled manner,
which may happen if the power domain drops the domain regulator.
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Darren Etheridge <detheridge@ti.com>
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

LCDC hardware does not support fb pitch that is different (i.e. larger)
than the screen size. The driver currently does no checks for this, and
the results of too big pitch are are flickering and lower fps.

This issue easily happens when using libdrm's modetest tool with non-32
bpp modes. As modetest always allocated 4 bytes per pixel, it implies a
bigger pitch for 16 or 24 bpp modes.

This patch adds a check to reject pitches the hardware cannot support.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Darren Etheridge <detheridge@ti.com>
Signed-off-by: Jyri Sarha <jsarha@ti.com>

Updating the tilcdc DRM driver code to calculate the LCD controller
pixel clock more accurately. Based on a suggested implementation by
Tomi Valkeinen.

The current code does not work correctly and produces wrong results
with many requested clock rates. It also oddly uses two different
clocks, a display pll clock and a divider clock (child of display
pll), instead of just using the clock coming to the lcdc.

This patch removes the use of the display pll clock, and rewrites the
code to calculate the clock rates. The idea is simply to request a
clock rate of pixelclock*2, as the LCD controller has an internal
divider which we set to 2.
Signed-off-by: Darren Etheridge <detheridge@ti.com>
[Rewrapped description]
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

rcar-du updates.

* 'drm/next/du' of git://linuxtv.org/pinchartl/fbdev: (281 commits)
  drm: rcar-du: Add tri-planar memory formats support
  drm: rcar-du: Add probe deferral debug messages
  drm: rcar-du: lvds: Add R-Car Gen3 support
  drm: rcar-du: lvds: Rename PLLEN bit to PLLON
  drm: rcar-du: lvds: Fix PLL frequency-related configuration
  drm: rcar-du: lvds: Avoid duplication of clock clamp code
  drm: rcar-du: Add R8A7795 device support
  drm: rcar-du: Output the DISP signal on the ODDF pin
  drm: rcar-du: Output the DISP signal on the DISP pin
  drm: rcar-du: Support up to 4 CRTCs
  drm: rcar-du: Drop LVDS double dependency on OF
  drm: rcar-du: Enable compilation on ARM64
  drm: rcar-du: Fix compile warning on 64-bit platforms
  drm: rcar-du: Expose the VSP1 compositor through KMS planes
  drm: rcar-du: Move plane allocator to rcar_du_plane.c
  drm: rcar-du: Restart the DU group when a plane source changes
  drm: rcar-du: Add VSP1 compositor support
  drm: rcar-du: Add VSP1 support to the planes allocator
  drm: rcar-du: Refactor plane setup
  drm: rcar-du: Compute plane DDCR4 register value directly
  ...

Those formats are supported on Gen3 only.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Print a message when the HDMI I2C slave encoder can't be found to help
debugging probe deferral issues.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The LVDS encoder differs slightly in Gen3 SoCs in its PLL configuration.
Add support for the Gen3 LVDS PLL parameters and startup procedure.
Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@renesas.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The bit is named PLLON in the datasheet, rename it.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The frequency checks don't match the datasheet, fix them.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Replace the duplicate code by a single central function.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Document the R8A7795-specific DT bindings and support them in the
driver. The HDMI and LVDS outputs are currently not supported.
Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@renesas.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The ODDF signal, output by default on the ODDF pin, isn't used on any
board supported in the kernel. As the Gen3 Salvator-X board uses the
ODDF pin as a DISP signal, hardcode that configuration in the driver.

Use of the ODDF signal will be implemented later through proper DT-based
configuration of the DU pins.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The DE signal is currently configured to be identical to the DISP
signal and is used for the same purpose. To make it clearer that the
DISP pin outputs the DISP signal, select it explicitly.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The Gen3 R8A7795 DU has 4 CRTCs, support them all.
Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@renesas.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

LVDS support depends on DRM_RCAR_DU which already depends on OF. Drop
the explicit dependency.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The R8A7795 SoC is ARM64-based and include a DU. Enable driver
compilation on ARM64.
Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@renesas.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Use %tu instead of %u to print difference between pointers.
Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@renesas.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

On R-Car Gen3 SoCs the DU lost its ability to access memory directly and
needs to work in conjunction with the VSP to do so. This commit handles
the VSP internally to hide it from the user.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The plane allocator is specific to DU planes and won't be used for
VSP-based planes, move it with the rest of the DU planes code where it
belongs.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Plane sources are configured by the VSPS bit in the PnDDCR4 register.
Although the datasheet states that the bit is updated during vertical
blanking, it seems that updates only occur when the DU group is held in
reset through the DSYSR.DRES bit. Restart the group if the source
changes.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Configure the plane source at plane setup time to source frames from
memory or from the VSP1.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The R8A7790 DU can source frames directly from the VSP1 devices VSPD0
and VSPD1. VSPD0 feeds DU0/1 plane 0, and VSPD1 feeds either DU2 plane 0
or DU0/1 plane 1.

Allocate the correct fixed plane when sourcing frames from VSPD0 or
VSPD1, and allocate planes in reverse index order otherwise to ensure
maximum availability of planes 0 and 1.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Rename plane setup functions using more explicit names, and use local
variables to store intermediate values to increase readability. This
also prepares for VSP compositor support.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

There's no need for a read-modify-write pattern, all register bits can
be set explicitly.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

A disabled CRTC can't display planes, the driver shouldn't try to
configure it when updating planes. The DRM core will store the plane
state for us, and the plane will be configured appropriately the next
time the CRTC is enabled.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The atomic framework guarantees that the CRTC enable and disable
functions will only be called when needed, there's no need to duplicate
the CRTC state check. By replacing the local CRTC enabled state check at
resume time with the CRTC active state we can remove the local CRTC
enabled state altogether.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The drm driver .load() operation is prone to race conditions as it
initializes the driver after registering the device nodes. Its usage is
deprecated, inline it in the probe function and call drm_dev_alloc() and
drm_dev_register() explicitly.

For consistency inline the .unload() handler in the remove function as
well.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>